The present invention relates to an adapter having a light-shielding shutter and an optical module receptacle having a light-shielding shutter, which are used for optical transmissions executed with optical fibers connected to an optical oscillating device such as a semiconductor laser, etc.
Oscillating light transmitted from an optical oscillating device such as a semiconductor laser, etc., is optically coupled to optical fibers, whereby optical transmissions have been carried out by transmitting the abovementioned oscillating light by the corresponding optical fibers. FIG. 11a is a front elevational view showing one example of an adapter for fitting an optical connector used for optical transmissions. FIG. 11b is a cross-sectional view of an adapter illustrated in FIG. 11a, which is taken along the line A-Axe2x80x2 therein. FIG. 11c is a view showing the bottom view of the adapter shown in FIG. 11a, which is partially cut off along the line Axe2x80x2-B therein. The adapter illustrated in FIG. 11a, 11b and 11c is an adapter that fits a SC connector used as an optical connector.
The adapter shown in these drawings FIG. 11a, FIG. 11b and FIG. 11c has two square-tubular housings 1 (1a and b). One end side of the respective housings 1a and b is constructed as an insertion port (optical fiber insertion port) of an optical connector, and the housing 1a and housing b are fixed so that the optical insertion port 2 and the opposite end side are caused to face each other. By inserting optical connectors from the optical insertion ports 2 of the respective housings 1a and 1b of the adapter along the tubular direction of the respective housings 1, the optical connectors are fitted to both end sides of the adapter. Thus, by the fitting of the optical connectors, it becomes possible to connect optical fibers secured in the respective optical connectors to each other.
Further, the respective housings 1a and 1b are provided with a cylindrical ferrule insertion tube 20 and connector engagement portions 15 equipped with an engagement claw 16 at the tip end side thereof. Where optical connectors are inserted into the abovementioned respective housings 1a and 1b, the tip end sides (connection end face sides) of the optical connectors are engaged by the connector engagement portions 15, and the end side of a ferrule secured at the optical connector is inserted into the ferrule insertion tube 20.
The optical fibers provided in one optical connector (for example, the optical connector inserted into and fitted to the housing 1b) of optical connectors inserted into and fitted to the abovementioned adapter are connected to the transmission portion side of an optical oscillating device and to the output side of an optical amplifier. The optical fibers transmits light transmitted from the optical oscillating device and light amplified by the optical amplifier, and outputs the light through the connection end face side of the optical connector.
The outputted light is transmitted through the ferrule insertion tube 20 as shown by the arrow line A shown in FIG. 11b and FIG. 11c, and enters an optical connector on the other side(in this case, the optical connector inserted into and fitted to the housing 1a).
Also, as shown in FIG. 11c, a bottom groove 10 is formed to fit a fixing metal fitting at the bottom outer wall 11 of the housing 11. Also, a side groove (not illustrated) is formed to fit a fixing metal fitting, which communicates with the abovementioned bottom groove 10, on the outer wall of both side portions of the housing 1. The fixing metal fitting to fix the abovementioned adapter at the fixing portion is provided with a plate provided along the bottom groove 10 of the housing 1 and a plate erect from the corresponding plate along both side walls of the housing 1, and the shape thereof is channel-shaped, wherein the abovementioned adapter can be fixed at the fixing portion by fitting the bottom groove 10 and side groove of the adapter to the fixing metal fitting.
Further, an optical receptacle used for optical transmissions has a housing whose structure is similar to that of the abovementioned housing 1, and is constructed so that a package in which an LD (laser diode) module is incorporated at the side opposed to the optical connector insertion port 2 of the housing. This type of an optical module receptacle is constructed so that an LD (laser diode) is incorporated in the abovementioned LD module package, and light transmitted from the LD is caused to enter the optical fibers of an optical connector fitted to the housing.
However, optical output of a semiconductor laser and an optical amplifier, which are used for optical transmissions, has been intensified in line with high bit rate transmissions in recent optical transmissions. For example, there are cases where the abovementioned optical output exceeds 100 mW through 1W.
There was a problem in that, in a case where an optical connector located at the side which receives light is disconnected by mistake during optical transmissions in which light of such high output is transmitted from the connection end face side of an optical connector fitted to one side of the adapter toward another optical connector fitted to the other side of the adapter, the light which is about to enter the optical connector side at the receiving side leaks from the optical connector insertion port 2 to the outside of the adapter.
Also, there was a problem similar to the above in the case where an optical connector fitted to the housing of the optical module receptacle is disconnected by mistake.
Therefore, in order to solve the abovementioned problems, for example, an adapter that is provided with a cover component 30 as shown in FIG. 12, has been proposed. The cover component 30 is to shield light that leaks through the optical connector insertion port 2 when the receiving side optical connector is disconnected. Also, reference number 29 in the drawing indicates an optical transmission portion, and reference number 31 indicates an optical connector fitted to the adapter.
However, in the proposal, since the cover component 30 has a complicated shape, it is difficult to produce an adapter having such a cover component, and production yield was not good. Further, the cover component 30 must be made of a special material to shield the light. Therefore, since a cover component 30 having a complicated shape must be made of a special material, there was another problem in that the cost of the adapter was increased.
Accordingly, the invention was developed to provide an adapter having an inexpensive light shielding shutter and an inexpensive and easily manufactured optical module receptacle having the same shutter, which is able to prevent light from leaking in cases where the light receiving side optical connector is disconnected.
That is, a first aspect of an adapter having a light shielding shutter according to the invention is an adapter having a tubular housing, in which one end portion of the corresponding housing is constructed as an insertion port of an optical connector, through which an optical connector is inserted along the tubular direction of the housing, wherein the adapter is provided with a roughly L-shaped shutter made of a resilient material and having a bottom plate secured along the bottom outer wall of the housing and an erectable portion which is erect from the corresponding bottom plate toward the corresponding optical connector insertion port side and interrupts light transmitted from the other end portion of the corresponding housing side toward the optical connector insertion port side, and a supporting plate having a bottom plate secured along the bottom outer wall of the housing and a side plate erect from the bottom plate along both side walls of the housing, the bottom plate of the shutter plate is placed between the bottom outer wall of the housing and the bottom plate of the supporting plate, the shutter is fixed in the housing by fixing the side plate of the supporting plate, the erectable portion of the shutter is folded in the bottom inner wall of the housing by the erectable portion of the shutter being inserted into an optical connector when the optical connector is inserted into the adapter to enable the light to enter the optical connector, and when the optical connector is not fitted in the adapter, the light is interrupted by the erectable portion of the shutter being made erect toward the optical connector insertion port side.
Also, a second aspect of an adapter having a light shielding shutter according to the invention is featured in that, in addition to the first aspect of an adapter having the light shielding shutter, a supporting plate fitting groove to which a side plate of the supporting plate is fitted is formed at the outer wall at both sides of the housing, and the side plates of the supporting plate are fitted to and fixed at the supporting plate fitting groove so that the outer plates at both side of the housing are placed between the side plates of the supporting plate.
Further, a third aspect of an adapter having a light shielding shutter according to the invention is featured in that, in addition to the first or second aspect of the adapter having the light shielding shutter, a guiding member provided with an insertion guiding portion which guides the insertion direction of optical connectors is mounted on the housing so as to cause the tip end side thereof to protrude forward from the optical connector insertion port of the housing.
In addition, a fourth aspect of an adapter having a light shielding shutter according to the invention is featured in that, in addition to the first or second aspect of the adapter having a light shielding shutter, a shutter plate insertion hole is formed halfway in the tubular direction of the housing on the bottom of the housing, and the erectable portion of the shutter plate is constructed so as to be erect from the shutter plate insertion hole into the tube of the housing, wherein the tubular hole of the housing from the optical connector insertion portion to the portion where the shutter plate insertion hole is formed is constructed as an insertion guiding portion which guides the insertion direction of optical connectors.
Further, a fifth aspect of an adapter having a light shielding shutter according to of the invention is featured in that, in addition to any one of the first through the fourth aspects of the adapter having a light shielding shutter, a cross-shaped portion is formed on the bottom portion plate of a supporting plate.
In the first through fifth aspects of an adapter having a light shielding shutter according to the invention, the adapter is provided with a tubular-shaped housing and a shutter plate equipped with an erectable portion which interrupts light transmitted toward the optical connector insertion port side of the corresponding housing. Therefore, when an optical connector is inserted into and fitted to an adapter, the erectable portion of the abovementioned shutter plate is folded toward the inner wall of the bottom portion of the housing by insertion of the optical connector, and light is allowed to enter the optical connector. Also, when the optical connector is not fitted to the adapter, the erectable portion of the shutter plate is erected toward the optical connector insertion port side by its resilient restorative force, thereby interrupting or shielding the light. Accordingly, even though the receiving side optical connector is disconnected by mistake during optical transmissions, light is shielded by the shutter plate, and it becomes possible to prevent the light from leaking from the optical connector insertion port to the outside.
A first aspect of an optical module receptacle having a light shielding shutter according to the invention is an optical module receptacle provided with a tubular housing, one end portion of which is constructed as an optical connector insertion portion through which an optical connector is inserted along the tubular direction of the housing, wherein the optical module receptacle is provided with a roughly L-shaped shutter plate made of a resilient material and having a bottom plate which is secured along the bottom outer wall of the housing and an erectable portion which is erect from the bottom plate toward the optical connector insertion port side and shields light transmitted from the other end side of the housing toward the optical connector insertion port side, and a supporting plate having a bottom plate secured along the bottom outer wall of the housing and a side plate erect along both side walls of the housing from the bottom plate, the bottom plate of the shutter plate is placed between the bottom outer wall of the housing and the bottom plate of the supporting plate, the shutter plate is fixed in the housing by fixing the side plate of the supporting plate, the erectable portion of the shutter plate is folded toward the bottom inner wall side of the housing by insertion of an optical connector when the optical connector is inserted into and fitted to the optical module receptacle to allow the light to enter the optical connector, and the erectable portion of the shutter plate is erected toward the optical connector insertion port side by its resilient restorative force to interrupt or shield the light.
Further, a second aspect of an optical module receptacle according to the invention is featured in that, in addition to the first aspect of an optical module receptacle according to the invention, a supporting plate fitting groove in which side plates of the supporting plate are provided at both side outer walls of the housing, and the side plates of the supporting plate are inserted into and fitted to the supporting plate fitting groove so that both side outer wall of the housing are placed therebetween.
Also, a third aspect of an optical module receptacle is featured in that, in addition to the first or second aspect of the optical module receptacle having a light shielding shutter, a guiding member equipped with an insertion guiding portion which guides the insertion direction of an optical connector is mounted on the housing so as to cause the tip end side thereof to protrude forward from the optical connector insertion port of the housing.
A fourth aspect of an optical module receptacle having a light shielding shutter according to the invention is featured in that, in addition to the first or second aspect of the optical module receptacle having a light shielding shutter, a shutter plate insertion hole is formed halfway in the tubular direction of the housing on the bottom of the housing, and the erectable portion of the shutter plate is constructed so as to be erect from the shutter plate insertion hole into the tube of the housing, wherein the tubular hole of the housing from the optical connector insertion portion to the portion where the shutter plate insertion hole is formed is constructed as an insertion guiding portion which guides the insertion direction of optical connectors.
Further, a fifth aspect of an optical module receptacle having a light shielding shutter according to the invention is featured in that, in addition to anyone of the first through the fourth aspects of the optical module receptacle having a light shielding shutter, a cross-shaped portion is formed on the bottom portion plate of a supporting plate.
In the first through fifth aspects of an optical module receptacle having a light shielding shutter according to the invention, as in the adapter having a light shielding shutter, the optical module receptacle is provided with a tubular-shaped housing and a shutter plate equipped with an erectable portion which interrupts light transmitted toward the optical connector insertion port side of the corresponding housing. Therefore, when an optical connector is inserted into and fitted to an optical module receptacle, the erectable portion of the abovementioned shutter plate is folded toward the inner wall of the bottom portion of the housing by insertion of the optical connector, and light is allowed to enter the optical connector. Also, when the optical connector is not fitted to the optical module receptacle, the erectable portion of the shutter plate is erected toward the optical connector insertion port side by its resilient restorative force, thereby interrupting or shielding the light. Accordingly, even though the receiving side optical connector is disconnected by mistake during optical transmissions, light can be shielded by the shutter plate.
Since a shutter plate, which constitutes the first through fifth aspects of an adapter having a light shielding shutter according to the invention and the first through fifth aspects of an optical module receptacle having a light shielding shutter according to the invention, is a roughly L-shaped shutter having a very simple shape or profile having the abovementioned erectable portion and bottom plate secured along the bottom outer wall of the housing, the production thereof is very easy.
Also, only by placing the shutter plate between the supporting plate provided with the bottom plate secured along the bottom outer wall of the housing and with the side plate erect from the corresponding bottom plate along both side walls of the housing and the bottom outer wall of the housing, and fixing the same shutter plate therebetween, the abovementioned shutter plate can be fixed in the housing. Thus, it is very easy to mount the shutter plate and supporting plate, wherein it is possible to easily produce the adapter having a light shielding shutter and optical module receptacle having the same at a high yield ratio.
Further, as described above, such a construction is employed, in which the shutter plate is made roughly L-shaped and it is supported and fixed in the housing by utilizing the supporting plate, whereby since the portion which must be made of a special material having an excellent light shielding property can be minimized, the production cost thereof can be accordingly reduced. Therefore, it is possible to provide an inexpensive adapter and an inexpensive optical module receptacle.
For example, conventionally, in order to prevent light from leaking where an optical connector is disconnected, a member which has both functions of the shutter plate and pressing plate was attached to the housing. The member was expensive and was formed of an ultra-resilient material such as, for example, NiTi, which is hard to be machined. On the contrary, in the invention, the shutter is made of an expensive ultra-resilient material NiTi, and the supporting plate is constructed of inexpensive stainless steel, etc., whereby the production can be further facilitated and the cost thereof can be decreased in comparison with the prior arts.
Also, in an adapter having a light shielding shutter and an optical module receptacle having the light shielding shutter according to the invention, by such a construction in which the side plates of the supporting plate are inserted into and fitted to the supporting plate fitting groove secured at the side outer wall of the housing, it is possible to further reliably attach the shutter plate in position.
Still further, an adapter having a light shielding shutter and an optical module receptacle having the light shielding shutter according to the invention employ such constructions in which a guiding member provided with an insertion guiding portion which guides the insertion direction of optical connectors is mounted in the housing, and in which a shutter plate insertion hole is formed on the bottom portion of the housing, the erectable portion of the shutter plate is made erect from the abovementioned shutter plate insertion hole toward the tubular hole side of the housing, and a tubular hole of the housing from the optical connector insertion port to the portion where the shutter plate insertion hole is formed is constructed as the abovementioned insertion guide member. Therefore, the insertion of optical connectors into the housing can be accurately guided by the insertion guiding portion, whereby the optical connectors can be accurately inserted, and the shutter plate can be accurately folded by optical connectors.
In addition, in an adapter having a light shielding shutter and an optical module receptacle having the light shielding shutter according to the invention, since a cross-shaped portion is formed on the bottom plate of the supporting plate, the supporting plate can be securely prevented from coming off with respect to the housing.